The invention disclosed herein pertains to a machine for filling bottles with liquid and, in particular, pertains to an improvement in the devices involved in cleansing and sterilizing the machine.
A typical high production machine for filling dozens of bottles simultaneously comprises a rotationally driven toroidal tank in which the filling liquid is stored under gas pressure. A plurality of filling units are mounted at equiangular spacing around the periphery of the tank. A turntable is positioned under the tank and rotates about the same axis. The turntable carries a circular array of bottle support disks equal in number to the number of filling units mounted to the tank. The disks are mounted to elevate the bottles to effect a seal between the mouth of the bottle and the filling unit before the bottle is subjected to pressurizing gas and before the liquid valve is open in the filling unit to allow liquid to flow into the bottle by gravity. The bottles on a linear conveyor are usually transferred by means of a warm conveyor to an infeed starwheel. The starwheel transfers the bottles to the bottle supports after which the bottles are lifted to seal to and be filled from the filling unit. After any particular bottle orbits around the tank, the lifting device that supports it is lowered and the bottle is transferred to an outfeed starwheel which may release the bottle successively to another linear conveyor.
There is a substantial amount of mechanisms involved in rotating the tank and controlling the lifting devices under the toroidal tank and within the confines of the circular array of filling units.
After the machine has made a long bottle filling run, it is stopped and prepared for cleansing and sterilizing it. Part of the cleaning operation involves removing all bottles from the machine and connecting the various passageways that conduct liquid and gases in the machine to a source of cleansing liquid. In a counterflow bottle filling machine, during normal filling operation, a gas injection and return tube is associated with each filling unit. Also, within the filling unit, there is a valve that allows liquid to flow after the injection and return tube has pressurized the interior of the bottle with an inert gas such as carbon dioxide. Every filling unit has some passageways connected to access liquid and gas from the toroidal storage tank. These passageways must be sterilized periodically. The gas injection and return tubes are, of course, open to the atmosphere before the backwashing or cleansing and sterilizing operation is to begin. The open ends of the gas tube must be blocked before the system is flushed with sterilizing and rinsing liquids. The most elementary approach to preparation for cleaning involves manually mounting a cup-like diverter member to each of the filling unit outlets to close off the end of the gas tube. During the filling operation, liquid is forced into the diverter cups and, because of the way the cups are connected, the flow direction of the incoming cleansing liquid is inverted or reversed and flows back into the various liquid and gas passageways for cleaning them. In the most advanced preexisting machines, there is a cylindrical shell or barrier wall mounted under the toroidal tank for protecting mechanisms inside of the barrier wall against splashing liquid and glass fragments that may be propelled by bottles that are cracked and explode when pressurized. In most prior machines, the diverter cups that are used in the washing and sterilization operation are parked outside of the barrier wall so that they can be undesirably filled with errant liquid as well as glass chips that are incidental to breakage of bottles occasionally during ordinary liquid filling runs. The completely unprotected diverter cups can themselves be damaged and soiled under normal filling machine operating conditions. Moreover, when the diverter cups are permanently parked outside of the barrier wall, they interfere with cleaning and sterilizing exterior surfaces of the machine in the filling unit region. This is undesirable because it is likely to result in improperly sterilized areas rather than germ-free areas. In other preexisting machines, the diverter cups are mounted directly on the bottle raising and lowering devices as in German Patent DE-OS 3722 495 or, in other preexisting machines, the diverter cups are mounted on the areas for the filling units as in German Patent DE-OS 2804 428.